Cosmetic container, inner lid with fiber sheet and method for manufacturing inner lid

ABSTRACT

A cosmetic container to store a cosmetic with a viscosity in a range of 2,000 cP to 60,000 cP is provided. The container comprises a container body to store the cosmetic and an inner lid having a frame to be attached to an opening of the container body and covered with an elastic fiber sheet. The fiber sheet when attached to the frame with a static state has a visible light transmittance equal to or smaller than 1.8%, and when the fiber sheet is stretched from the static state to have an area as much as 1.05 times larger than that of the static state, the visible light transmittance of the fiber sheet become equal to or greater than 2.0%.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority upon Japanese Patent Application No. 2015-175493 filed on Sep. 7, 2015, which is herein incorporated by reference.

BACKGROUND Technical Field

The present invention relates to a cosmetic container suitable to store a cosmetic with fluidity and viscosity, an inner lid to be used with the cosmetic container and a method for manufacturing the inner lid.

Related Art

There are cosmetics having various physical properties from a solid to a liquid, and various types of cosmetic containers have been developed to store these cosmetics according to the physical property of the cosmetics.

Liquid cosmetics with very high fluidity are stored in bottle containers, creamy cosmetics with a relatively low viscosity with fluidity are stored in tube containers, and solid cosmetics or powder cosmetics with high viscosity and without fluidity are generally stored in compact containers.

Low viscosity cosmetics with fluidity are widely used recently, but most of these cosmetics are stored in tube containers without mirror. When using a facial cosmetic stored in a tube container, however, a mirror is needed. Therefore, the cosmetic in the tube container is difficult to use compared to cosmetics stored in compact container having a mirror.

Japanese Patent Application Laid-open publication No. 2008-194190 and Japanese Utility Model Application Publication No. 7-43575 disclose cosmetic containers in which a paste or powder form cosmetic without fluidity is stored in a container body and a ring-shaped lid covered with mesh is provided at the upper open end of the container body. In these cosmetic containers, a puff is used to push down the mesh against the tension of the mesh from above to take out the cosmetic in the container body through the mesh.

However, since a ratio of open spaces of the mesh is large at approximately 40% to 60% of the total area of the mesh, when the cosmetic with low viscosity and having fluidity is contained in the container body covered with the lid and held with the lid of the cosmetic container being in a reversed state for a long time, the cosmetic will pass through the mesh and leak outside, thus the above could not be used to store such cosmetic.

SUMMARY

An aspect of the present invention provides a cosmetic container that makes possible to store a cosmetic with low viscosity having fluidity in a container body with an open upper end without leaking the cosmetic from inside of the container body even when the container body is held in a reversed state for a long time, and that the cosmetic can be easily taken out from the container body by using a puff when necessary.

In an aspect of this invention, a cosmetic with viscosity in a range of 2,000 cP to 60,000 cP is mentioned herein as a cosmetic with low viscosity and fluidity. However, preferable range of viscosity of the cosmetic to be stored in the present cosmetic container is 2,000 cP to 30,000 cP. A cosmetic container according to this invention comprises a container body to store the cosmetic with low viscosity and fluidity and an inner lid having a frame to be attached to an opening of the container body and covered with an elastic fiber sheet. The fiber sheet when attached to the frame with a static state has a visible light transmittance equal to or smaller than 1.8%, and when the fiber sheet is stretched from the static state to have an area as much as 1.05 times larger than that of the static state, the visible light transmittance of the fiber sheet become equal to or greater than 2.0%.

The fiber sheet is preferably formed from braided fibers and, more preferably, the fiber sheet is formed from warp knitting.

Further, preferably main fiber of the fiber sheet is polyester or nylon, and sub-fiber thereof is polyurethane. In respect to mixing ratio of the main fiber, in the case that polyester is used as the main fiber, polyester is preferably included equal to or greater than 85%, and in the case that nylon is used as the main fiber, nylon is preferably included equal to or greater than 87%.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an exploded perspective view of a cosmetic container according to an embodiment of the present invention;

FIG. 2A is a perspective view showing a partially assembled state of the cosmetic container according to the above embodiment, FIG. 2B is a perspective view showing the entire cosmetic container in an assembled state, and FIG. 2C is a vertical cross-sectional view of FIG. 2B;

FIGS. 3A and 3B (collectively referred to as FIG. 3) is a diagram showing a measurement device of visible light transmittance of a fiber sheet of the above embodiment;

FIG. 4A is a vertical cross-sectional view showing the fiber sheet attached to a lower surface of a frame, and FIG. 4B is across-sectional view showing a state where a tension is applied to a central part of the fiber sheet in a direction intersecting a surface thereof; and

FIGS. 5A and 5B (collectively referred to as FIG. 5) is a schematic view showing molds for injection molding of the inner lid.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A cosmetic container 1 according to an embodiment of the present invention includes, as shown in FIG. 1, a container body 4 open in an upper end thereof, an outer lid 2 that hermetically seals an opening of the container body 4, and an inner lid 3 that is to be attached inside the container body 4. The container body 4 is configured from a shallow cup-shaped part 41 to store a cosmetic and a cylindrical neck part 42 that extends upwards from the cup-shaped part 41. An external thread 43 is formed to an outer periphery of the neck part 42, and an inner peripheral surface 44 of the cup-shaped part is formed cylindrically. An internal thread that screws to the external thread 43 is formed to an inner peripheral surface of the outer lid 2 (refer to FIG. 2C), and a mirror 20 is attached to an inner lower surface of the outer lid 2. The inner lid 3 has a shallow cylindrical frame 31 with an outer peripheral surface 32 that contacts the inner peripheral surface 44 of the container body 4, and an elastic fiber sheet 10 is attached to the lower end 35 of the frame 31 to cover the cylindrical frame 3. An upper end of the frame 31 is provides with an outwardly extending brim 33. As shown in FIG. 2C, when the inner lid 3 is attached inside the container body 4, the lower surface of the brim 33 of the frame 31 comes to contact with an upper end face of the container body 4. In this way, the inner lid 3 does not fall inside the container body 4. By attaching the inner lid 3 to the container body 4 and hermetically sealing the container body 4 with the outer lid 2, the cosmetic container 1 with the external appearance as shown in FIG. 2B is obtained.

In this embodiment, the fiber sheet 10 is attached at a peripheral upper end surface thereof to the lower end 35 of the frame 31 as shown in FIG. 2C. A lower surface of this fiber sheet 10 is arranged to be spaced apart upwards from an inner bottom surface 45 of the container body 4 with a space D1, which space D1 becomes substantially a storing space of a cosmetic 5. The cosmetic 5 initially stored in the container body 4 shall be such an amount that the cosmetic does not contact the lower surface of the fiber sheet 10, namely, such that a slight space is formed below the fiber sheet 10. It should be noted that, in the embodiment shown in FIG. 2C, the depth in the vertical direction of the frame 31 of the inner lid 3 is formed slightly larger than half the depth of the container body, and the upper side of the fiber sheet 10 inside the frame 31 is made as a space to store a puff (not shown).

The fiber sheet 10 of the inner lid 3 is preferably formed by warp knitting of fibers of equal to or smaller than 500 denier, and openings formed by the warp knitting are so small that they cannot be visually observed. The degree of the openings can be measured with a visible light transmittance to be described later. The fiber sheet is preferably formed from a warp knitted tricot having an excellent elasticity and flexibility. As the fibers for the sheet 10, preferably, polyester or nylon is used as a main fiber and polyurethane is used as a sub-fiber.

In an embodiment of this invention, when the cosmetic with low viscosity and fluidity is stored in the container body 4 and closed with the inner lid at the upper end thereof, it becomes necessary that even when the stored cosmetic is held for a long period of time with the container body being inverted, the fiber sheet 10 has to prevent the cosmetic from leaking through the fiber sheet 10. Further, when the cosmetic container is held in a normal state as shown in FIG. 2(C) and a central part of the fiber sheet 10 is pressed downward for a predetermined amount with such as a puff, the openings between the fibers of the sheet 10 are widen, and the cosmetic that is stored inside the container body can seep upward through the openings of the fiber sheet and adheres to the puff such that the cosmetic can be easily taken out.

Then, according to the invention, changes of width of the openings between fibers of the sheet 10 due to elasticity of the sheet are focused on, and an appropriate degree of openings and the changes thereof are measured with the visible light transmittance.

FIG. 3 shows a device for measuring the visible light transmittance through the fiber sheet. Initially, a sample fiber sheet 111 having elasticity is mounted to a measurement frame 110, which corresponds to the frame 31 of the inner lid 3, with a predetermined tension referred hereinafter. The measurement device 100 has a light source part 101 and a measuring part 102, and the fiber sheet 111 that is mounted to the measurement frame 110 as above is placed between the light source part 101 and the measuring part 102. Light from the light source part passes through the fiber sheet and is received by a light-receiving element integrated in the measuring part 102.

The intensity of light through the fiber sheet measured by the light-receiving part is compared with an original intensity of light measured without the fiber sheet and thus a visible light transmittance of the fiber sheet is calculated therefrom and the measuring part 102 outputs and displays the above calculation results. For the measurement of the visible light transmittance, a known device (“HA-TR” made by Suga Test Instruments Co. Ltd. in Japan) on the market is used.

As shown in FIG. 3B, the width w at the periphery of the measurement frame 110 is made wide to make it easy to attach the fiber sheet. An inner diameter Ø₂ of the measurement frame 110 is 7 cm. Here, a sample 111 of fiber sheet is cut in a circular shape to be slightly larger than the inner diameter Ø₂ of the frame. The above state of the sample sheet, which is circular and not expanded, is called herein as “initial state” of the fiber sheet and has an area (S₀). Next, the peripheral edge of the sample sheet 111 is adhered to one end face of the measurement frame 110 under a predetermined low tension so as not to allow the sample sheet to slack. The above predetermined tension is a tension which expands an area of the sample sheet as much as 1.05 times of that of the initial state and this expanded state is called as “static state” of the fiber sheet. FIG. 4A shows the fiber sheet 10 in the static state adhered to the lower end of the frame 31 having a diameter of Ø₁.

FIG. 4B is a view showing the fiber sheet 10 pressed downwards at the center part thereof toward the cosmetic in the container body. As shown in FIG. 4A, the sheet 10 is a circle with a diameter Ø₁ (=7 cm) in the static state, and the area is π (Ø₁/2)² (hereinafter, referred to as S₁) of the circle with the diameter Ø₁. On the other hand, as shown in FIG. 4B, when the center part of the sheet 10 is pressed to a predetermined depth D₂, the sheet 10 deforms to a cone shape. Thus, the flat area (S₁) of the sheet 10 changed to an area of the side surface of this cone (hereinafter, referred to as S₂), as calculated below.

S ₂=π·(Ø₁/2)·{(Ø₁/2)² +D ₂ ²}^(1/2)

In the calculation, when the fiber sheet 10 in the static state which has an area S₁ (=1) is pressed as shown in FIG. 4(B) so that the depth D₂ of the fiber sheet becomes to 1 cm, the area ratios S₂/S₁ before and after the pressing become 1.05. Therefore, when measuring the visible light transmittance using the above device to reproduce the tension when the fiber sheet 10 of the inner lid 3 of the cosmetic container is pressed to the depth D₂=1 cm, the sample fiber sheet in the initial state has to be expanded to an area of 1.05×1.05≈1.10 times. Namely, the sample fiber sheet in the initial state has to be stretched 1.05 times up to the static state and then the same sample fiber sheet in the static state has to be further stretched 1.05 times to reproduce the depressed state as shown in FIG. 4(B). Thus, the sample fiber sheet stretched as much as 1.10 times from the initial state is attached to the measurement frame.

According to the invention, nine different types of fiber sheets (I to IX) are selected and three types of tests have been conducted on these fiber sheets so as to evaluate a leakage of cosmetic through the fiber sheet, an easiness of extraction of the cosmetic through the fiber sheet and degrading of the fiber sheet.

The test of the leakage is made to know whether the cosmetic stored in the container body may leak when the container body is held inverted. In this test, each type of nine fiber sheets is set to a frame with a tension of the static state set forth above and visual light transmittance of each fiber sheet was measured first.

Then a cosmetic that has relatively low viscosity of 2000 cP was placed on each fiber sheet for 24 hours and the leakage of the cosmetic through each fiber sheet is visually inspected. It was evaluated that the fiber sheet without any trace of leakage is satisfactory.

As to the test of the easiness of extraction, each type of nine fiber sheets is stretched from the static state to have an area as much as 1.05 times larger than that of the static state and visual light transmittance of each fiber sheet was measured. Then, each fiber sheet is attached to an open end of a container body filled with cosmetic having relatively low viscosity of 60,000 cP and the fiber sheet was repeatedly depressed with the use of puff against the cosmetic. At the time the cosmetic in the container body stops seeping out to the upper surface of the fiber sheet, an amount of the remaining cosmetic is measured. When the remaining amount is equal to or less than 10% of the original amount, it was evaluated as satisfactory.

Another test of degrading is a test whether or not the fiber sheet becomes wavy or slack after a long period of time, and this is a problem of the fiber itself and is considered to depend on the amount of polyurethane. Although polyurethane is mixed with other fibers in order to enhance the elasticity of the fiber sheet, it is known that when a certain amount polyurethane contacts to cosmetic, the elasticity thereof is degraded and the surface of the fiber sheet become wavy or slack. Such wave will not affect so much to the leakage of the cosmetic and the easiness of extraction of the cosmetic but it will degrade the appearance of the cosmetic to be used. Therefore, the surface conditions of the fiber sheets containing polyurethane were observed and those fiber sheets not generating the waves or slacks after the repeated test of the easiness of extraction were considered acceptable.

The results are shown in Table below.

VISIBLE LIGHT TRANSMITTANCE (%) TEST RESULTS MIXING RATE (%) STATIC STATIC LEAK POLY- STATE OF STATE WHEN SAMPLE POLYESTE NYLON URETHANE FIBER SHEET ×1.05 INVERTED EXTRACTION DEGRADING I 80 20 1.3 2.0 ◯ ◯ X II 85 15 1.8 5.3 ◯ ◯ ◯ III 89 11 1.5 3.3 ◯ ◯ ◯ IV 90 10 1.6 5.2 ◯ ◯ ◯ V 92 8 2.2 5.0 X ◯ ◯ VI 100 0 1.0 1.9 ◯ X ◯ VII 87 13 1.6 2.1 ◯ ◯ ◯ VIII 100 0 3.1 7.1 X ◯ ◯ IX 19 81 44 51.9 X ◯ X

As shown in the Table above, in the tests whether the cosmetic in the container body leaks when the container body is held inverted, samples V, VIII and IX having visible light transmittances at the initial state of 2.2, 3.1 and 44.0, respectively, showed the leakage. The other samples which had visible light transmittance equal to or less than 1.8 did not show leakage. From the above results, it could be noted that the visible light transmittance at the initial state of the sheet fibers of equal to or less than 1.8 will be satisfactory. In the other test of easiness of extraction of the cosmetic through the fiber sheet, only sample VI, in which the visual light transmittance of static state×1.05 is equal to 1.9, showed unsatisfactory result. From this result, it could be noted that visible light transmittance of equal to or more than 2.0 will be satisfactory for the fiber sheets that were stretched as much as 1.05 times from the static state.

It could be also noted that the conventional mesh of sample IX used to the inner lid showed the light transmittance of 44.0 in the static state, which value is by far the largest than the other samples and that the mesh cannot be used to the inner lid of the container of the cosmetic having low viscosity and fluidity.

From the above results, it could be noted that the fiber sheet when attached to the frame with the static state should have a visible light transmittance equal to or smaller than 1.8%, and when the fiber sheet is stretched from the static state to have an area as much as 1.05 times larger than that of the static state, the visible light transmittance of the fiber sheet should become equal to or greater than 2.0%.

From the test of the degradation of the fiber sheets, it could be noted that when the amount of polyurethane contained in the fiber sheet exceeds 20%, the degrading will occur but such degradation will not occur when the amount thereof is 15%.

As a result, it could be noted that in the case that polyester is used as the main fiber, polyester is preferably included by equal to or greater than 85%, and in the case that nylon is used as the main fiber, nylon is preferably included by equal to or greater than 87%.

In the above embodiment of this invention, the cosmetic container is described in which the container body is opened and closed by screwing the outer lid from above to the container body, but this invention is not limited to the above container and can be applied to typical compact containers in which a hinge is used to open and close a container body by a lid.

Reference is now made to a method of manufacturing the inner lid with reference to FIG. 5 showing a mold in vertical cross section for forming the inner lid, in which FIG. 5A shows the mold 50 in an open state, and FIG. 5B shows the mold 50 in a closed state.

As shown in FIG. 5A, the mold 50 is configured from a first mold 51 that is fixed at the lowest position, a second mold 52 arranged above the first mold 51 to be moved up and down, and a third mold 53 arranged above the second mold 52 to be moved up and down. The second mold 52 is provided with a cylindrical cavity 55 that goes along the outer shape of a frame. The third mold 53 is fixed with a core 56 to form a hollow part of the frame. In this example, a fiber sheet 111 is provided with a predetermined tension between the first mold 51 and the second mold 52. The predetermined tension set forth above is a tension to provide the static state of the fiber sheet when molded to the frame.

As shown in FIG. 5B, when the mold 50 is closed, the core 56 is inserted into the cylindrical cavity 55 in the second mold 52 as shown in FIG. 5A and a hollow cylindrical cavity 60 in the shape of the frame having a brim-shaped space 61 to an upper end is formed. Further, the fiber sheet 111 is sandwiched between an upper end face 57 of the first mold 51 and a lower end face 58 of the core 56. Also, a channel for supplying a melted resin from a runner to a gate 62 is formed.

When the melted resin is injected via the gate 62 into the cavity 60, the melted resin under pressure seep through the fiber sheet 111 arranged to the lower end of the cavity 60 and becomes integral with the resin in the cavity. Thus, when the resin cools, the resin sets in a shape of the frame integral with the fiber sheet 11. Then, the mold 50 is opened to separate from the gate 62 and the fiber sheet 111 is cut along the outer shape of the circular lower end of the frame to complete the inner lid 3 in FIG. 1. 

What is claimed is:
 1. A cosmetic container comprising: a container body to store a cosmetic with a viscosity in a range of 2,000 cP to 60,000 cP; and an inner lid having a frame to be attached to an opening of the container body and covered with an elastic fiber sheet; wherein the fiber sheet when attached to the frame with a static state has a visible light transmittance equal to or smaller than 1.8%, and when the fiber sheet is stretched from the static state to have an area as much as 1.05 times larger than that of the static state, the visible light transmittance of the fiber sheet become equal to or greater than 2.0%.
 2. The cosmetic container according to claim 1, wherein the fiber sheet is formed from braided fibers.
 3. The cosmetic container according to claim 2, wherein the fiber sheet is formed from warp knitting.
 4. The cosmetic container according to claim 2 or 3, wherein a main fiber of the fiber sheet is made of polyester or nylon, and a sub-fiber is made of polyurethane.
 5. The cosmetic container according to claim 4, wherein in the case that polyester is used as the main fiber, polyester is included equal to or greater than 85%.
 6. The cosmetic container according to claim 4, wherein in the case that nylon is used as the main fiber, nylon is included equal to or greater than 87%.
 7. An inner lid for a container body for storing a cosmetic, wherein the inner lid has a frame to be attached to an opening of the container body; the fiber sheet when attached to the frame with a static state has a visible light transmittance equal to or smaller than 1.8%; and when the fiber sheet is stretched from the static state to have an area as much as 1.05 times larger than that of the static state, the visible light transmittance of the fiber sheet become equal to or greater than 2.0%.
 8. A method for manufacturing an inner lid for cosmetic container comprising: selecting a flexible fiber sheet which has a visible light transmittance of equal to or less than 1.8% at a static state of the fiber sheet where the fiber sheet has been stretched from an initial sate of the fiber sheet to have an area (S₁) of 1.05 times larger than an area (S₀) at an initial state, said fiber sheet also having a visible light transmittance equal to or more than 2.0% when the fiber sheet is further stretched from the static state so as to have an area 1.05×S₁; stretching the fiber sheet from the area S₀ to the area S₁; and adhering a peripheral end surface of the fiber sheet, which is kept to the stretched static state, to an end surface of a frame. 